In pesticidal formulations, wettable powders, water dispersible granules, water soluble formulations and the like are solid formulations, but they are applied to the objected plants, cultivated soil and the like as their diluted solution after diluted with water. The solid formulations enveloped in water soluble polymer film or water soluble paper, which can be applied into water to give a dilution as they are, are described for the purpose of preventing a drift of the solid formulations and further saving labor when preparing the dilution (cf. JP-sho60-61504A, JP-sho60-45180A, etc.).
However, these enveloped pesticidal formulations are not sufficiently stable. It was troublesome that the envelope material may degenerate while they are preserved for a long time and may be broken while preserved or transported, and further a sprayer may be blocked in case of applying the dilution to plants.